U.S. Pat. No. 5,879,827, the disclosure of which is incorporated herein by reference, discloses nanostructured elements comprising acicular microstructured support whiskers bearing acicular nanoscopic catalyst particles. The catalyst particles may comprise alternating layers of different catalyst materials which may differ in composition, in degree of alloying or in degree of crystallinity.
U.S. Pat. No. 6,482,763, the disclosure of which is incorporated herein by reference, discloses fuel cell electrode catalysts comprising alternating platinum-containing layers and layers containing suboxides of a second metal that display an early onset of CO oxidation.
U.S. Pat. Nos. 5,338,430, 5,879,828, 6,040,077 and 6,319,293, the disclosures of which are incorporated herein by reference, also concern nanostructured thin film catalysts.
U.S. Pat. Nos. 4,812,352, 5,039,561, 5,176,786, and 5,336,558, the disclosures of which are incorporated herein by reference, concern microstructures.
U.S. patent application Ser. No. 10/674,594, issuing Sep. 2, 2008, as U.S. Pat. No. 7,419,741, the disclosure of which is incorporated herein by reference, discloses fuel cell cathode catalysts comprising nanostructures formed by depositing alternating layers of platinum and a second layer onto a microstructure support, which may form a ternary catalyst.
U.S. patent application Ser. No. 11/248,561, the disclosure of which is incorporated herein by reference, discloses fuel cell cathode catalysts comprising microstructured support whiskers bearing nanoscopic catalyst particles comprising platinum and manganese and at least one other metal at specified volume ratios and Mn content, where other metal is typically Ni or Co.
U.S. patent application Ser. Nos. 10/945,178 and 10/944,998, the disclosures of which are incorporated herein by reference, discloses fuel cell membrane electrode assemblies and fuel cell polymer electrolyte membranes comprising bound anionic functional groups and Mn or Ru cations or comprising manganese oxides which demonstrate increased durability.
Some investigators report the use of iridium containing catalysts for oxygen evolution. The following reference may be relevant to such a technology: “Performance of a PEM water electrolysis cell using IrxRuyTazO2 electrocatalysts for the oxygen evolution electrode,” International Journal of Hydrogen Energy, volume 32, Issue 13, September 2007, pp 2320-2324. “Electrochemical characterization of IrxSn1-xO2 powders as oxygen evolution electro catalysts,” Electrochimica Acta, Volume 51, Issue 15, April 2006, pp 3161-3167.
Some investigators report the use of sputtered iridium oxide in certain electrocatalysts. The following references may be relevant to such a technology: “Sputtered iridium oxide films as electrocatalysts for water splitting via PEM electrolysis,” E. Slavcheva, I Radev, S. Bliznakov, G. Topalov, P. Andreev and E. Budevski, Electrochimica Acta 52 (2007) pp 3389-3894. “Multicomponent Electrodes for Water Oxidation: From Combinatorial to Individual Electrode Study,” Alexandre G. Dokoutchaev, Feraz Abdelrazzaq, and Mark E. Thompson, Chem. Mater. 2002, 14, 3343-3348. “Platinum-Iridium Alloys as Oxygen Reduction Electrocatalysts for Polymer Electrolyte Fuel Cells,” Tsutomu Ioroi and Kazuaki Yasuda, Journal of Electrochemical Soc. 152 (10) A1917-A1924 (2005). “Reactively Sputtered Iridium Oxide—Influence of plasma excitation and substrate temperature on morphology, composition and electrochemical characteristics,” Borge Wessling, Astrid Besmehn, Wilfried Mokwa, and Uwe Schnakenberg, Journal of Electrochemical Soc. 154 (5) F83-F89 (2007).
Some investigators report the use of iridium black in a fuel cell anode. The following reference may be relevant to such a technology: S. A. Grigoriev, P. Millet, V. N. Fateev, Journal of Power Sources 177 (2008), 282-285.